The top federal prosecutor for New Orleans has removed himself from the case of four conservative activists arrested last week while trying to capture hidden camera footage in a senator's office, the Department of Justice said Monday.

A Justice Department news release said Jim Letten, U.S. Attorney for the Eastern District of Louisiana, recused himself from the case a day after the Jan. 25 arrests in Democrat Sen. Mary Landrieu's office in New Orleans. Letten's toplieutenant, assistant U.S. Attorney Jan Mann, has taken over.